Flight instrument



Sept. 5, 1944. B. G. CARLSON 2,357,381

FLIGHT INSTRUMENT Filed April 29, 1943 ZJ) 2 f4 f INVENTOR. 5f/f7 664/?50/1/ Patented Sept. 5, 1944 FLIGHT INSTRUMENT A Bert G. Carlson, Erieside, Ohio, assignor to Jack da Heintz, Inc., Bedfor Ohio d, Ohio', a corporation of ApplicationApril 29, 1943, Serial N0. 485,085

2 Claims.' ('Cl. 33-204) This invention relates in general to automatic pilot gyros and more particularly to improvements in directional gyrus.

One oi' the primary objects of the invention is to provide a directional gyro with means for auto..

matically controlling and making constant thev speed of rotation of the gyro wheel so that the precessional eect will be uniform under the same amount and degree of turns of the aircraftl carrying the automatic pilot.'

\Another important object is to provide further means for such uniformity by predeterminedly spring loading the gyro and also providing automatic temperature compensation'for such spring loading means by which the rate of turn as well as the amount of turn may be accuratelygdetermined and appropriately indicated.

and the speed of rotation of the gyro wheel de- With the foregoing and other objects in view,

the invention resides in the combination of parts and in the details of construction hereinafter set forth in the following description and appended claims, certain embodiments thereof being .illustrated in the accompanying drawing, .in which:

Figure 1 is a view i'n cross section taken through the directional gyro box and gimbai frame. showing the gyro wheel in top plan view; and

Figure 2 is a partial view in section through the gyro wheel and one pivot bearing taken along line 2--2 of Figure 1.

Referring more particularly to the drawing, ythe gyro box I houses bearing assemblies 2 and 3 for pivots 4 and 5 of a gimbal frame 6 which. in turn, houses bearing assemblies 1 and 8 for pivots 9 and I0 of the shaft of a directional gyro wheel I2.

The gyro wheel may be air spun, in which event the air` may be drawn in by suction through a passage I3 in the pivot 4, thenceA through passages I4, I5, I6 and I1 in the gimbal frame and thence through passage I8 in shaft to and through a restricted jet I9 adjacent the buckets of the gyro wheel I2.

As a means for automatically controlling and making uniform the speed of rotation of the gyro wheel, there is provided an extension shaft 2| rotating with the gyro wheel shaft II. This shaft 2| carries a plate 22 to which are pivotally attached at 23 and 24, two or more pivoted weighted arms 2.5 and 26 in the nature of a speed governor. Surrounding shaft 2|, to rotate therewith, is a sleeve 21 which bears against a com- 3| and 32 of sleeve 21 when the latter is in the normal position shown in Figure 1.

When, however, the speed of rotation of the gyro wheel exceeds a certain predetermined amount the two pivoted weights 25 and 26 move upwardly and outwardly as they rotate with the shaft I |,.due to centrifugal force and as they do they exert a downward pressure on the sleeve 21 against the action of spring 28. This brings the sleeve apertures 3| and 32 out of registry with passages I5 and I6 and thus the supply of incoming air to the jet I9 and the buckets is cut 01T. 'I'his reduces the pressure air iiow on the buckets creases. This decrease of speed of rotation lessens the centrifugal force tending to keep the weights 25 and 26 maintained upwardand outward and the spring 28 forces sleeve 21 upwardly to bring its ports 3| and 32 in registry with passages I5 and I6, as shown in Figure 1, restoring.

the normal flow of air to maintain the normal desired predetermined speed of rotation of the lgyro wheel.

As stated before, the gyro is spring loaded to resist precession and means are provided for temperature compensation of such spring loading. This is accomplished by securing a plate 45 by means of bolts 46 to the gimbal 6. This plate is apertured to receive a ball 41 to which is secured a tension coil spring 48 to the other end of which is secured a bali 49 fitting in a recess,

ment there 'is provided an adjustable set screw 55 bearing inwardly against the element 52.

I claim: 4

1. In a directional indicator for aircraft showing the direction and amount of deviation from course, comprising a two-degree-of-freedom gyro pression coil spring 28 between the same and a l collar 29 resting on pivot 3. Shaft 2| is provided with an aperture 30 extending therethrough to register with vpassages I5 and I6 and apertures mounted for precession through an angle proportional to the .rate of turn of the aircraft. said gyro being provided with resilient constraining means, said constraining means comprising a pivoted lever carried bythe housing. of said gyro and a tension spring secured to one free end thereof and the movable support for said gyro for permitting procession of said gyro, and adjustable bimetallic spring means bearing resiliently inwardly on the other end of said pivoted lever for maintaining said spring under tension and varygyro being provided with resilient constraining means, said constraining means comprising a pivoted lever carried by the housing of said gyro and a tension spring secured to a free end thereof and the movable support for said 4gyro for yieldingly opposing precession of said gyro,. andadjustable bimetallic means for automatically oompensating for temperature changes and the efrect that such changes would otherwise have on the force of said resilient constraining means, said adjustable bimetallic means being secured to said housing and bearing on said lever lto maintain said spring under tension.

, -BERT G. CARLSON. 

